SERS Resolving of the Significance of Acetate on the Enhanced Catalytic Activity of Nanozymes

Understanding the structure-activity correlation and reaction mechanism of the catalytic process in an acetic acid-sodium acetate (HAc-NaAc) buffer environment is crucial for the design of efficient nanozymes. Here, we first reported a lattice restructuration of Au-LaNiO3-delta nanofibers (NFs) after acid-ification with the HAc-NaAc buffer to show a significantly enhanced oxidase-like property. Surface-enhanced Raman spec-troscopy (SERS) and density functional theory (DFT) calculation confirm the direct evidence for the formation of specific enhanced intermediate O-O species after acidification, indicating that the insertion of the carboxyl group in the A-Au/LaNiO3-delta NFs plays crucial roles in both producing vacancies in HAc-NaAc solution from its dissociation during the catalytic process and the protection of the vacancies, which can be directly interacted with oxygen in the environment to produce O-O species, realizing the enhanced oxidation of substrate molecules. The insertion of the carboxyl group increased the oxidase-like catalytic activity by 2.38 times and the SERS activity by 5.27 times. This strategy offers a way to construct an efficient nanozyme-linked immunosorbent assay system for the diagnosis of cancer through the highly sensitive SERS identification of exosomes.

Automated summary

Understanding the catalytic process in an acetic acid-sodium acetate buffer environment is crucial for designing efficient nanozymes. This study investigated the lattice restructuration of Au-LaNiO3-delta nanofibers after acidification and revealed the role of carboxyl group insertion in enhancing oxidase-like activity and protecting vacancies. The strategy offers potential for constructing an efficient nanozyme-linked immunosorbent assay system.